In this work, a new triazine-based covalent organic framework (COF) was synthesized and further modified by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to obtain a 'honeycomb-like' DOPO@COF material, which was used as flame retardant (FR) for epoxy resin (EP). Surprisingly, DOPO@COF overcomes the ineffective effect of DOPO on smoke release inhibition and the weak flame retardancy of COF. DOPO@COF can exhibit suppression of smoke and harmful gases while effectively reducing heat release. When incorporating 3 wt% of DOPO@COF into the EP (0.2 wt% phosphorus content), significant reductions of 39.0% in peak heat release rate (pHRR), 18.7% in total heat release rate (THR), 20.6% in peak CO production rate (pCOPR), and 38.7% in peak CO2 production rate (pCO2PR) were observed. Moreover, the introduction of DOPO@COF effectively enhances the storage modulus, crosslinking density and the tensile and impact strength of EP composite. This work provides a new research idea for the development of N, P synergistic EP FRs for nanomaterials based on DOPO and triazine-based COFs.

中文翻译：

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“蜂窝状”三嗪基共价有机框架衍生物显著提高环氧树脂的阻燃性和机械性能


在这项工作中，合成了一种新的三嗪基共价有机框架 （COF），并通过 9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物 （DOPO） 进一步改性，得到一种“蜂窝状”DOPO@COF材料，用作环氧树脂 （EP） 的阻燃剂 （FR）。令人惊讶的是，DOPO@COF克服了 DOPO 对烟雾释放抑制的无效作用和 COF 的弱阻燃性。DOPO@COF可以抑制烟雾和有害气体，同时有效减少热量释放。当在 EP 中加入 3 wt% 的 DOPO@COF（磷含量为 0.2 wt%）时，观察到峰值热释放率 （pHRR） 降低 39.0%，总热释放率 （THR） 降低 18.7%，峰值 CO 生成速率 （pCOPR） 降低 20.6%，峰值 CO2 生成速率 （pCO2PR） 降低 38.7%。此外，DOPO@COF的引入有效地提高了极压复合材料的储能模量、交联密度以及拉伸和冲击强度。这项工作为基于 DOPO 和三嗪基 COF 的纳米材料 N、P 协同 EP FRs 的开发提供了新的研究思路。